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[PMID]:28732013
[Au] Autor:Luo M; Yang S; Li X; Liu P; Xue J; Zhou X; Su K; Xu X; Qing Y; Qiu J; Li Y
[Ad] Endereço:School of Public Health and Management, Chongqing Medical University, Chongqing, China.
[Ti] Título:The KP1_4563 gene is regulated by the cAMP receptor protein and controls type 3 fimbrial function in Klebsiella pneumoniae NTUH-K2044.
[So] Source:PLoS One;12(7):e0180666, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Klebsiella pneumoniae (K. pneumoniae) is an opportunistic pathogen that can adhere to host cells or extracellular matrix via type 1 and type 3 fimbriae. KP1_4563 is a gene encoding a hypothetical protein in K. pneumoniae NTUH-K2044. KP1_4563 is located between the type 1 and type 3 fimbrial gene clusters and is likely associated with fimbrial function given its putative conserved domains of unknown function (DUF1471). Cyclic AMP receptor protein (CRP) regulates virulence-related gene expression and is a crucial transcriptional regulator in many bacteria. The predicted DNA recognition motif of CRP is present in the KP1_4563 promoter region. This study aimed to investigate the function of KP1_4563 in fimbriae and its transcriptional regulation mechanism by CRP. We generated Kp-Δ4563 mutant and complementation strains. We utilized phenotype and adhesion assays to evaluate the role of KP1_4563 in fimbriae. We conducted quantitative RT-PCR (qRT-PCR), LacZ fusion, electrophoretic mobility shift, and DNase I footprinting assays to study the transcriptional regulation of KP1_4563 gene by CRP. We found that KP1_4563 negatively regulates the function of type 3 fimbriae. Compared with NTUH-K2044, the absence of KP1_4563 enhanced the ability of Kp-Δ4563 to adhere to A549 cells. CRP negatively regulates KP1_4563 by directly binding to its promoter region. KP1_4563 plays an important role in type 3 fimbrial function. This novel insight will assist in the development of strategies for preventing K. pneumoniae infection.
[Mh] Termos MeSH primário: Proteína Receptora de AMP Cíclico/metabolismo
Proteínas de Fímbrias/metabolismo
Klebsiella pneumoniae/genética
Klebsiella pneumoniae/metabolismo
[Mh] Termos MeSH secundário: Aderência Bacteriana/fisiologia
Pegada de DNA
Desoxirribonuclease I/metabolismo
Ensaio de Desvio de Mobilidade Eletroforética
Escherichia coli
Regulação da Expressão Gênica/fisiologia
Testes de Hemaglutinação
Óperon Lac
Mananas/química
Fenótipo
Reação em Cadeia da Polimerase em Tempo Real
Saccharomyces cerevisiae
Deleção de Sequência
Transcrição Genética/fisiologia
beta-Galactosidase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclic AMP Receptor Protein); 0 (Mannans); 147680-16-8 (Fimbriae Proteins); EC 3.1.21.1 (Deoxyribonuclease I); EC 3.2.1.23 (beta-Galactosidase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170927
[Lr] Data última revisão:
170927
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170722
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0180666


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[PMID]:28245055
[Au] Autor:Sim DW; Choi JW; Kim JH; Ryu KS; Kim M; Yu HW; Jo KS; Kim EH; Seo MD; Jeon YH; Lee BJ; Kim YP; Won HS
[Ad] Endereço:Department of Biotechnology, Research Institute (RIBHS) and College of Biomedical and Health Science, Konkuk University, Chungju, Chungbuk, Korea.
[Ti] Título:C-terminal dimerization of apo-cyclic AMP receptor protein validated in solution.
[So] Source:FEBS Lett;591(7):1064-1070, 2017 Apr.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Although cyclic AMP receptor protein (CRP) has long served as a typical example of effector-mediated protein allostery, mechanistic details into its regulation have been controversial due to discrepancy between the known crystal structure and NMR structure of apo-CRP. Here, we report that the recombinant protein corresponding to its C-terminal DNA-binding domain (CDD) forms a dimer. This result, together with structural information obtained in the present NMR study, is consistent with the previous crystal structure and validates its relevance also in solution. Therefore, our findings suggest that dissociation of the CDD may be critically involved in cAMP-induced allosteric activation of CRP.
[Mh] Termos MeSH primário: Apoproteínas/química
Proteína Receptora de AMP Cíclico/química
Proteínas de Escherichia coli/química
Domínios Proteicos
Multimerização Proteica
Soluções/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Apoproteínas/genética
Apoproteínas/metabolismo
Dicroísmo Circular
AMP Cíclico/química
AMP Cíclico/metabolismo
Proteína Receptora de AMP Cíclico/genética
Proteína Receptora de AMP Cíclico/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Espectroscopia de Ressonância Magnética
Modelos Moleculares
Ligação Proteica
Estrutura Secundária de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Apoproteins); 0 (Cyclic AMP Receptor Protein); 0 (Escherichia coli Proteins); 0 (Recombinant Proteins); 0 (Solutions); E0399OZS9N (Cyclic AMP)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170601
[Lr] Data última revisão:
170601
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170301
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12613


  3 / 1144 MEDLINE  
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[PMID]:28188293
[Au] Autor:Lanfranco MF; Gárate F; Engdahl AJ; Maillard RA
[Ad] Endereço:From the Department of Chemistry, Georgetown University, Washington, D. C. 20057.
[Ti] Título:Asymmetric configurations in a reengineered homodimer reveal multiple subunit communication pathways in protein allostery.
[So] Source:J Biol Chem;292(15):6086-6093, 2017 Apr 14.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Many allosteric proteins form homo-oligomeric complexes to regulate a biological function. In homo-oligomers, subunits establish communication pathways that are modulated by external stimuli like ligand binding. A challenge for dissecting the communication mechanisms in homo-oligomers is identifying intermediate liganded states, which are typically transiently populated. However, their identities provide the most mechanistic information on how ligand-induced signals propagate from bound to empty subunits. Here, we dissected the directionality and magnitude of subunit communication in a reengineered single-chain version of the homodimeric transcription factor cAMP receptor protein. By combining wild-type and mutant subunits in various asymmetric configurations, we revealed a linear relationship between the magnitude of cooperative effects and the number of mutant subunits. We found that a single mutation is sufficient to change the global allosteric behavior of the dimer even when one subunit was wild type. Dimers harboring two mutations with opposite cooperative effects had different allosteric properties depending on the arrangement of the mutations. When the two mutations were placed in the same subunit, the resulting cooperativity was neutral. In contrast, when placed in different subunits, the observed cooperativity was dominated by the mutation with strongest effects over cAMP affinity relative to wild type. These results highlight the distinct roles of intrasubunit interactions and intersubunit communication in allostery. Finally, dimers bound to either one or two cAMP molecules had similar DNA affinities, indicating that both asymmetric and symmetric liganded states activate DNA interactions. These studies have revealed the multiple communication pathways that homo-oligomers employ to transduce signals.
[Mh] Termos MeSH primário: Proteína Receptora de AMP Cíclico/química
AMP Cíclico/química
DNA Bacteriano/química
Proteínas de Escherichia coli/química
Escherichia coli/química
Multimerização Proteica/fisiologia
Transdução de Sinais/fisiologia
[Mh] Termos MeSH secundário: Regulação Alostérica/fisiologia
AMP Cíclico/genética
AMP Cíclico/metabolismo
Proteína Receptora de AMP Cíclico/genética
Proteína Receptora de AMP Cíclico/metabolismo
DNA Bacteriano/genética
DNA Bacteriano/metabolismo
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Mutação
Estrutura Quaternária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclic AMP Receptor Protein); 0 (DNA, Bacterial); 0 (Escherichia coli Proteins); 0 (crp protein, E coli); E0399OZS9N (Cyclic AMP)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170428
[Lr] Data última revisão:
170428
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170212
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.776047


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[PMID]:27989220
[Au] Autor:Graff SM; Bentley WE
[Ad] Endereço:* Institute of Bioscience and Biotechnology Research, University of Maryland, College Park, MD 20742, USA.
[Ti] Título:Mathematical model of LsrR-binding and derepression in Escherichia coli K12.
[So] Source:J Bioinform Comput Biol;15(1):1650039, 2017 Feb.
[Is] ISSN:1757-6334
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Quorum sensing (QS) enables bacterial communication and collective behavior in response to self-secreted signaling molecules. Unlocking its genetic regulation will provide insight towards understanding its influence on pathogenesis, formation of biofilms, and many other phenotypes. There are few datasets available that link QS-mediated gene expression to its regulatory components and even fewer mathematical models that incorporate known mechanistic detail. By integrating these data with annotated sequence information, mathematical inferences can be pieced together that shed light on regulatory structure. A first principles model, developed here for the E. coli QS system, builds on known mechanistic detail and is used to develop a working model of LuxS-regulated (Lsr) activity. That is, our model is meant to discriminate among hypothetical mechanisms governing lsr transcriptional regulation. Our simulations are in qualitative agreement with experimentally observed data. Importantly, our results point to the importance of transcriptional regulator, LsrR, cycling on genetic control. We also found several experimental observations in E. coli and homologous systems that were not explained by current mechanistic understanding. For example, by comparing simulations with reports of the integrating host factor in Aggrigatibacter actinomycetemcomitans, we conclude that additional transcriptional components are likely involved. An iterative process of simulation and experiment, therefore, is needed to inform new experiments and incorporate new model detail, the benefit of which will more rapidly validate mechanistic understanding.
[Mh] Termos MeSH primário: Escherichia coli K12/genética
Proteínas de Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
Modelos Biológicos
Percepção de Quorum
Proteínas Repressoras/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
AMP Cíclico/genética
AMP Cíclico/metabolismo
Proteína Receptora de AMP Cíclico/genética
Proteína Receptora de AMP Cíclico/metabolismo
Escherichia coli K12/metabolismo
Proteínas de Escherichia coli/genética
Homosserina/análogos & derivados
Homosserina/metabolismo
Lactonas/metabolismo
Mutagênese
Mutação
Óperon
Multimerização Proteica
Proteínas Repressoras/genética
beta-Galactosidase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclic AMP Receptor Protein); 0 (Escherichia coli Proteins); 0 (Lactones); 0 (LsrR protein, E coli); 0 (N-octanoylhomoserine lactone); 0 (Repressor Proteins); 0 (crp protein, E coli); 6KA95X0IVO (Homoserine); E0399OZS9N (Cyclic AMP); EC 3.2.1.23 (beta-Galactosidase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171023
[Lr] Data última revisão:
171023
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161220
[St] Status:MEDLINE
[do] DOI:10.1142/S0219720016500396


  5 / 1144 MEDLINE  
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[PMID]:27943535
[Au] Autor:De la Cruz MA; Ruiz-Tagle A; Ares MA; Pacheco S; Yáñez JA; Cedillo L; Torres J; Girón JA
[Ad] Endereço:Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI IMSS, Mexico City, Mexico.
[Ti] Título:The expression of Longus type 4 pilus of enterotoxigenic Escherichia coli is regulated by LngR and LngS and by H-NS, CpxR and CRP global regulators.
[So] Source:Environ Microbiol;19(5):1761-1775, 2017 May.
[Is] ISSN:1462-2920
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Enterotoxigenic Escherichia coli produces a long type 4 pilus called Longus. The regulatory elements and the environmental signals controlling the expression of Longus-encoding genes are unknown. We identified two genes lngR and lngS in the Longus operon, whose predicted products share homology with transcriptional regulators. Isogenic lngR and lngS mutants were considerably affected in transcription of lngA pilin gene. The expression of lngA, lngR and lngS genes was optimally expressed at 37°C at pH 7.5. The presence of glucose and sodium chloride had a positive effect on Longus expression. The presence of divalent ions, particularly calcium, appears to be an important stimulus for Longus production. In addition, we studied H-NS, CpxR and CRP global regulators, on Longus expression. The response regulator CpxR appears to function as a positive regulator of lng genes as the cpxR mutant showed reduced levels of lngRSA expression. In contrast, H-NS and CRP function as negative regulators since expression of lngA was up-regulated in isogenic hns and crp mutants. H-NS and CRP were required for salt- and glucose-mediated regulation of Longus. Our data suggest the existence of a complex regulatory network controlling Longus expression, involving both local and global regulators in response to different environmental signals.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Toxinas Bacterianas/metabolismo
Escherichia coli Enterotoxigênica/patogenicidade
Proteínas de Escherichia coli/metabolismo
Fímbrias Bacterianas/metabolismo
Redes Reguladoras de Genes/genética
Transativadores/metabolismo
[Mh] Termos MeSH secundário: Toxinas Bacterianas/genética
Proteína Receptora de AMP Cíclico/metabolismo
Proteínas de Ligação a DNA/metabolismo
Escherichia coli Enterotoxigênica/genética
Escherichia coli Enterotoxigênica/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Fímbrias/genética
Fímbrias Bacterianas/genética
Regulação Bacteriana da Expressão Gênica/genética
Transativadores/genética
Fatores de Virulência/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Bacterial Toxins); 0 (Cyclic AMP Receptor Protein); 0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (LngA protein, E coli); 0 (LngR protein, E coli); 0 (LngS protein, E coli); 0 (Trans-Activators); 0 (Virulence Factors); 0 (crp protein, E coli); 147680-16-8 (Fimbriae Proteins); 153554-07-5 (CpxR protein, Bacteria)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161213
[St] Status:MEDLINE
[do] DOI:10.1111/1462-2920.13644


  6 / 1144 MEDLINE  
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[PMID]:27902401
[Au] Autor:Ou Q; Fan J; Duan D; Xu L; Wang J; Zhou D; Yang H; Li B
[Ad] Endereço:1​School of Basic Medicine, Hubei University of Medicine, Shiyan, Hubei 442000, PR China.
[Ti] Título:Involvement of cAMP receptor protein in biofilm formation, fimbria production, capsular polysaccharide biosynthesis and lethality in mouse of Klebsiella pneumoniae serotype K1 causing pyogenic liver abscess.
[So] Source:J Med Microbiol;66(1):1-7, 2017 Jan.
[Is] ISSN:1473-5644
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The global regulator cAMP receptor protein (CRP) has been shown to be required for the full virulence and/or for the expression of virulence determinants in a wide set of bacterial pathogens. In this work, the crp mutant as well as the complemented mutant was constructed from a wild-type Klebsiella pneumoniae capsular serotype K1 strain causing the primary pyogenic liver abscess. The phenotypes of wild-type strain, crp mutant and complemented mutant were characterized systematically. It was disclosed that K. pneumoniae CRP was required for the in vitro growth, fimbria production, biofilm formation and lethality in mouse, but it inhibited the capsular polysaccharide biosynthesis. These indicated the important roles of CRP in regulating the expression of virulence and biofilm genes in K. pneumoniae.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Proteína Receptora de AMP Cíclico/metabolismo
Fímbrias Bacterianas/metabolismo
Klebsiella pneumoniae/patogenicidade
Abscesso Hepático Piogênico/microbiologia
[Mh] Termos MeSH secundário: Animais
Cápsulas Bacterianas/metabolismo
Proteínas de Bactérias/genética
Biofilmes/crescimento & desenvolvimento
Proteína Receptora de AMP Cíclico/genética
Feminino
Deleção de Genes
Regulação Bacteriana da Expressão Gênica
Klebsiella pneumoniae/genética
Klebsiella pneumoniae/metabolismo
Abscesso Hepático Piogênico/patologia
Camundongos
Camundongos Endogâmicos BALB C
Polissacarídeos Bacterianos
RNA Bacteriano/genética
Sorotipagem
Virulência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cyclic AMP Receptor Protein); 0 (Polysaccharides, Bacterial); 0 (RNA, Bacterial)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170320
[Lr] Data última revisão:
170320
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161201
[St] Status:MEDLINE
[do] DOI:10.1099/jmm.0.000391


  7 / 1144 MEDLINE  
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[PMID]:27698083
[Au] Autor:Hufnagel DA; Evans ML; Greene SE; Pinkner JS; Hultgren SJ; Chapman MR
[Ad] Endereço:Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
[Ti] Título:The Catabolite Repressor Protein-Cyclic AMP Complex Regulates csgD and Biofilm Formation in Uropathogenic Escherichia coli.
[So] Source:J Bacteriol;198(24):3329-3334, 2016 Dec 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The extracellular matrix protects Escherichia coli from immune cells, oxidative stress, predation, and other environmental stresses. Production of the E. coli extracellular matrix is regulated by transcription factors that are tuned to environmental conditions. The biofilm master regulator protein CsgD upregulates curli and cellulose, the two major polymers in the extracellular matrix of uropathogenic E. coli (UPEC) biofilms. We found that cyclic AMP (cAMP) regulates curli, cellulose, and UPEC biofilms through csgD The alarmone cAMP is produced by adenylate cyclase (CyaA), and deletion of cyaA resulted in reduced extracellular matrix production and biofilm formation. The catabolite repressor protein (CRP) positively regulated csgD transcription, leading to curli and cellulose production in the UPEC isolate, UTI89. Glucose, a known inhibitor of CyaA activity, blocked extracellular matrix formation when added to the growth medium. The mutant strains ΔcyaA and Δcrp did not produce rugose biofilms, pellicles, curli, cellulose, or CsgD. Three putative CRP binding sites were identified within the csgD-csgB intergenic region, and purified CRP could gel shift the csgD-csgB intergenic region. Additionally, we found that CRP binded upstream of kpsMT, which encodes machinery for K1 capsule production. Together our work shows that cAMP and CRP influence E. coli biofilms through transcriptional regulation of csgD IMPORTANCE The catabolite repressor protein (CRP)-cyclic AMP (cAMP) complex influences the transcription of ∼7% of genes on the Escherichia coli chromosome (D. Zheng, C. Constantinidou, J. L. Hobman, and S. D. Minchin, Nucleic Acids Res 32:5874-5893, 2004, https://dx.doi.org/10.1093/nar/gkh908). Glucose inhibits E. coli biofilm formation, and ΔcyaA and Δcrp mutants show impaired biofilm formation (D. W. Jackson, J.W. Simecka, and T. Romeo, J Bacteriol 184:3406-3410, 2002, https://dx.doi.org/10.1128/JB.184.12.3406-3410.2002). We determined that the cAMP-CRP complex regulates curli and cellulose production and the formation of rugose and pellicle biofilms through csgD Additionally, we propose that cAMP may work as a signaling compound for uropathogenic E. coli (UPEC) to transition from the bladder lumen to inside epithelial cells for intracellular bacterial community formation through K1 capsule regulation.
[Mh] Termos MeSH primário: Biofilmes
Proteína Receptora de AMP Cíclico/metabolismo
AMP Cíclico/metabolismo
Proteínas de Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
Transativadores/metabolismo
Escherichia coli Uropatogênica/fisiologia
[Mh] Termos MeSH secundário: Proteína Receptora de AMP Cíclico/genética
Proteínas de Escherichia coli/genética
Regiões Promotoras Genéticas
Ligação Proteica
Transativadores/genética
Escherichia coli Uropatogênica/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (CsgD protein, E coli); 0 (Cyclic AMP Receptor Protein); 0 (Escherichia coli Proteins); 0 (Trans-Activators); 0 (crp protein, E coli); E0399OZS9N (Cyclic AMP)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170718
[Lr] Data última revisão:
170718
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161005
[St] Status:MEDLINE


  8 / 1144 MEDLINE  
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[PMID]:27551019
[Au] Autor:Pannuri A; Vakulskas CA; Zere T; McGibbon LC; Edwards AN; Georgellis D; Babitzke P; Romeo T
[Ad] Endereço:Department of Microbiology and Cell Science, University of Florida, Institute of Food and Agricultural Sciences, Gainesville, Florida, USA.
[Ti] Título:Circuitry Linking the Catabolite Repression and Csr Global Regulatory Systems of Escherichia coli.
[So] Source:J Bacteriol;198(21):3000-3015, 2016 Nov 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cyclic AMP (cAMP) and the cAMP receptor protein (cAMP-CRP) and CsrA are the principal regulators of the catabolite repression and carbon storage global regulatory systems, respectively. cAMP-CRP controls the transcription of genes for carbohydrate metabolism and other processes in response to carbon nutritional status, while CsrA binds to diverse mRNAs and regulates translation, RNA stability, and/or transcription elongation. CsrA also binds to the regulatory small RNAs (sRNAs) CsrB and CsrC, which antagonize its activity. The BarA-UvrY two-component signal transduction system (TCS) directly activates csrB and csrC (csrB/C) transcription, while CsrA does so indirectly. We show that cAMP-CRP inhibits csrB/C transcription without negatively regulating phosphorylated UvrY (P-UvrY) or CsrA levels. A crp deletion caused an elevation in CsrB/C levels in the stationary phase of growth and increased the expression of csrB-lacZ and csrC-lacZ transcriptional fusions, although modest stimulation of CsrB/C turnover by the crp deletion partially masked the former effects. DNase I footprinting and other studies demonstrated that cAMP-CRP bound specifically to three sites located upstream from the csrC promoter, two of which overlapped the P-UvrY binding site. These two proteins competed for binding at the overlapping sites. In vitro transcription-translation experiments confirmed direct repression of csrC-lacZ expression by cAMP-CRP. In contrast, cAMP-CRP effects on csrB transcription may be mediated indirectly, as it bound nonspecifically to csrB DNA. In the reciprocal direction, CsrA bound to crp mRNA with high affinity and specificity and yet exhibited only modest, conditional effects on expression. Our findings are incorporated into an emerging model for the response of Csr circuitry to carbon nutritional status. IMPORTANCE: Csr (Rsm) noncoding small RNAs (sRNAs) CsrB and CsrC of Escherichia coli use molecular mimicry to sequester the RNA binding protein CsrA (RsmA) away from lower-affinity mRNA targets, thus eliciting major shifts in the bacterial lifestyle. CsrB/C transcription and turnover are activated by carbon metabolism products (e.g., formate and acetate) and by a preferred carbon source (glucose), respectively. We show that cAMP-CRP, a mediator of classical catabolite repression, inhibits csrC transcription by binding to the upstream region of this gene and also inhibits csrB transcription, apparently indirectly. We propose that glucose availability activates pathways for both synthesis and turnover of CsrB/C, thus shaping the dynamics of global signaling in response to the nutritional environment by poising CsrB/C sRNA levels for rapid response.
[Mh] Termos MeSH primário: Repressão Catabólica
Proteínas de Escherichia coli/metabolismo
Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
RNA Longo não Codificante/metabolismo
Proteínas de Ligação a RNA/metabolismo
Proteínas Repressoras/metabolismo
[Mh] Termos MeSH secundário: Proteína Receptora de AMP Cíclico/genética
Proteína Receptora de AMP Cíclico/metabolismo
Escherichia coli/genética
Proteínas de Escherichia coli/genética
RNA Bacteriano/genética
RNA Bacteriano/metabolismo
RNA Longo não Codificante/genética
Proteínas de Ligação a RNA/genética
Proteínas Repressoras/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (CsrA protein, E coli); 0 (CsrB RNA, E coli); 0 (CsrC RNA, E coli); 0 (Cyclic AMP Receptor Protein); 0 (Escherichia coli Proteins); 0 (RNA, Bacterial); 0 (RNA, Long Noncoding); 0 (RNA-Binding Proteins); 0 (Repressor Proteins)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170613
[Lr] Data última revisão:
170613
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160824
[St] Status:MEDLINE


  9 / 1144 MEDLINE  
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[PMID]:27535647
[Au] Autor:Lee C; Kim J; Kwon M; Lee K; Min H; Kim SH; Kim D; Lee N; Kim J; Kim D; Ko C; Park C
[Ad] Endereço:Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon 305-701, Republic of Korea.
[Ti] Título:Screening for Escherichia coli K-12 genes conferring glyoxal resistance or sensitivity by transposon insertions.
[So] Source:FEMS Microbiol Lett;363(18), 2016 Sep.
[Is] ISSN:1574-6968
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Glyoxal (GO) belongs to the reactive electrophilic species generated in vivo in all organisms. In order to identify targets of GO and their response mechanisms, we attempted to screen for GO-sensitive mutants by random insertions of TnphoA-132. The genes responsible for GO susceptibility were functionally classified as the following: (i) tRNA modification; trmE, gidA and truA, (ii) DNA repair; recA and recC, (iii) toxin-antitoxin; mqsA and (iv) redox metabolism; yqhD and caiC In addition, an insertion in the crp gene, encoding the cAMP responsive transcription factor, exhibits a GO-resistant phenotype, which is consistent with the phenotype of adenylate cyclase (cya) mutant showing GO resistance. This suggests that global regulation involving cAMP is operated in a stress response to GO. To further characterize the CRP-regulated genes directly associated with GO resistance, we created double mutants deficient in both crp and one of the candidate genes including yqhD, gloA and sodB The results indicate that these genes are negatively regulated by CRP as confirmed by real-time RT-PCR. We propose that tRNA as well as DNA are the targets of GO and that toxin/antitoxin, antioxidant and cAMP are involved in cellular response to GO.
[Mh] Termos MeSH primário: Elementos de DNA Transponíveis
Escherichia coli K12/efeitos dos fármacos
Glioxal/farmacologia
Mutagênese Insercional
[Mh] Termos MeSH secundário: Adenilil Ciclases/genética
Proteína Receptora de AMP Cíclico/genética
Farmacorresistência Bacteriana/genética
Escherichia coli K12/genética
Proteínas de Escherichia coli/genética
Glioxal/metabolismo
Mutação
RNA de Transferência/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclic AMP Receptor Protein); 0 (DNA Transposable Elements); 0 (Escherichia coli Proteins); 0 (crp protein, E coli); 50NP6JJ975 (Glyoxal); 9014-25-9 (RNA, Transfer); EC 4.6.1.1 (Adenylyl Cyclases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171024
[Lr] Data última revisão:
171024
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160819
[St] Status:MEDLINE


  10 / 1144 MEDLINE  
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[PMID]:27475664
[Au] Autor:Ye W; Zhong Z; Zhu S; Zheng S; Xiao J; Song S; Yu H; Wu Q; Lin Z; Chen J
[Ad] Endereço:Department of Orthopaedic Spinal Surgery, Nanfang Hospital, Southern Medical University, China.
[Ti] Título:Advanced oxidation protein products induce catabolic effect through oxidant-dependent activation of NF-κ B pathway in human chondrocyte.
[So] Source:Int Immunopharmacol;39:149-157, 2016 Oct.
[Is] ISSN:1878-1705
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Advanced oxidation protein products (AOPPs) have been shown to participate in the progression of rheumatoid arthritis (RA). However, the effect of AOPPs accumulation on catabolic effect in human chondrocyte and the underlying mechanism(s) remain unclear. The present study demonstrated that AOPPs inhibited cell viability and glycosaminoglycan (GAG) production in human chondrocyte. Exposure of chondrocyte to AOPPs significantly increased the production of catabolic factors, such as cyclooxygenase-2 (COX-2), matrix metalloproteinase 3 (MMPs)-3 and MMP-13. AOPPs stimulation induced ROS generation and NF-κ B p65 phosphorylation, which could be inhibited by soluble receptor for advanced glycan end products (sRAGE), NADPH oxidase inhibitor (apocynin), ROS scavenger (N-acetyl-cysteine, NAC). Furthermore, NF-κ B inhibitor Bay11-7082 significantly reversed the AOPPs-induced expression of catabolic factors and phosphorylation of NF-κ B p65. Targeting AOPPs-triggered catabolic effect might be as a promising option for patients with RA.
[Mh] Termos MeSH primário: Produtos da Oxidação Avançada de Proteínas/metabolismo
Artrite Reumatoide/metabolismo
Condrócitos/fisiologia
Proteína Receptora de AMP Cíclico/metabolismo
NF-kappa B/metabolismo
[Mh] Termos MeSH secundário: Idoso
Inibidores de Ciclo-Oxigenase 2/metabolismo
Feminino
Produtos Finais de Glicação Avançada/metabolismo
Glicosaminoglicanos/metabolismo
Seres Humanos
Masculino
Metaloproteinase 13 da Matriz/metabolismo
Metaloproteinase 3 da Matriz/metabolismo
Meia-Idade
NF-kappa B/antagonistas & inibidores
Nitrilos/farmacologia
Oxirredução
Transdução de Sinais/efeitos dos fármacos
Sulfonas/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (3-(4-methylphenylsulfonyl)-2-propenenitrile); 0 (Advanced Oxidation Protein Products); 0 (Cyclic AMP Receptor Protein); 0 (Cyclooxygenase 2 Inhibitors); 0 (Glycation End Products, Advanced); 0 (Glycosaminoglycans); 0 (NF-kappa B); 0 (Nitriles); 0 (Sulfones); EC 3.4.24.- (Matrix Metalloproteinase 13); EC 3.4.24.17 (Matrix Metalloproteinase 3)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160801
[St] Status:MEDLINE



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